The NtfsDisableLastAccessUpdate registry setting is enabled by default in Windows 7. This was a performance tweak that many people used in earlier OSes because it prevents a lot of excessive writes to the hard drive.
If you actually want the Last Access date updated the way it used to be, simply set the registry value to 0.
For future reference in case the doc link stops working, the key is located in:
It's a REG_DWORD value called
NtfsDisableLastAccessUpdate that can be set to 0 or 1.
From the link:
Determines whether NTFS updates the last-access timestamp on each directory when it lists the directories on an NTFS volume.
This entry is designed to prevent the NTFS log buffer in physical memory from becoming filled with timestamp update records. If you have an NTFS volume with a very large number of directories (in excess of 70,000), and Windows 2000 does not respond quickly to dir commands, adding this entry to the registry might make directories list faster.
0 - When listing directories, NTFS updates the last-access timestamp on each directory it detects, and it records each time change in the NTFS log.
1 - When listing directories, NTFS does not update the last-access timestamp, and it does not record time stamp updates in the NTFS log.